diff --git a/src/js/components/tree.jsx b/src/js/components/tree.jsx
index 6525c08..032d701 100644
--- a/src/js/components/tree.jsx
+++ b/src/js/components/tree.jsx
@@ -2,12 +2,29 @@ import React from 'react'
 import Branch from './branch.jsx'
 import { isElementVisible } from '../lib'
 
+const MIN_RESIZE_WIDTH = 55
+const MAX_RESIZE_WIDTH = 700
+
+const widthLocalStorageKey = '__better_github_pr_tree_width'
+
 class Tree extends React.Component {
   constructor (props) {
     super(props)
 
     this.onClose = this.onClose.bind(this)
     this.onScroll = this.onScroll.bind(this)
+    this.onResizerMouseDown = this.onResizerMouseDown.bind(this)
+    this.onMouseMove = this.onMouseMove.bind(this)
+    this.onMouseUp = this.onMouseUp.bind(this)
+    this.toggleDocumentFullWidth = this.toggleDocumentFullWidth.bind(this)
+
+    this.isResizing = false
+    this.resizeDelta = 0
+
+    this.treeContainer = document.querySelector('.__better_github_pr')
+    this.reviewContainers = document.querySelectorAll('.enable_better_github_pr .diff-view, .enable_better_github_pr .commit.full-commit.prh-commit')
+
+    this.setInitialWidth()
 
     this.state = {
       show: true,
@@ -20,6 +37,10 @@ class Tree extends React.Component {
     window.addEventListener('load', this.onScroll, false)
     window.addEventListener('scroll', this.onScroll, false)
     window.addEventListener('resize', this.onScroll, false)
+
+    this.resizer.addEventListener('mousedown', this.onResizerMouseDown, false)
+    document.addEventListener('mousemove', this.onMouseMove, false)
+    document.addEventListener('mouseup', this.onMouseUp, false)
   }
 
   componentWillUnmount () {
@@ -27,6 +48,33 @@ class Tree extends React.Component {
     window.removeEventListener('load', this.onScroll, false)
     window.removeEventListener('scroll', this.onScroll, false)
     window.removeEventListener('resize', this.onScroll, false)
+
+    this.resizer.removeEventListener('mousedown', this.onResizerMouseDown, false)
+    document.removeEventListener('mousemove', this.onMouseMove, false)
+    document.removeEventListener('mouseup', this.onMouseUp, false)
+  }
+
+  onResizerMouseDown () {
+    this.isResizing = true
+    this.treeContainer.classList.add('__better_github_pr_noselect')
+    this.prevWidth = this.treeContainer.offsetWidth
+    this.startResizeX = this.resizer.getBoundingClientRect().x
+  }
+
+  onMouseMove (e) {
+    if (!this.isResizing) return
+
+    this.resizeDelta = e.clientX - this.startResizeX
+    let newWidth = this.prevWidth + this.resizeDelta
+    setTimeout(() => this.setWidth(newWidth), 0)
+  }
+
+  onMouseUp () {
+    if (!this.isResizing) return
+
+    this.isResizing = false
+    this.treeContainer.classList.remove('__better_github_pr_noselect')
+    window.localStorage.setItem(widthLocalStorageKey, this.treeContainer.offsetWidth)
   }
 
   onScroll () {
@@ -45,6 +93,30 @@ class Tree extends React.Component {
     const show = false
     this.setState({ show })
     document.body.classList.toggle('enable_better_github_pr', show)
+    this.setWidth(0, false)
+  }
+
+  setInitialWidth () {
+    const savedWitdh = window.localStorage.getItem(widthLocalStorageKey)
+    if (savedWitdh) {
+      this.setWidth(parseInt(savedWitdh, 10))
+    }
+  }
+
+  setWidth (width, withConstraints = true) {
+    if (withConstraints) {
+      if (width <= MIN_RESIZE_WIDTH) width = MIN_RESIZE_WIDTH
+      if (width >= MAX_RESIZE_WIDTH) width = MAX_RESIZE_WIDTH
+    }
+
+    this.treeContainer.style.width = `${width}px`
+    this.reviewContainers.forEach((element) => {
+      element.style['margin-left'] = `${width + 10}px`
+    })
+  }
+
+  toggleDocumentFullWidth () {
+    document.querySelector('body').classList.toggle('__better_github_pr_wide')
   }
 
   render () {
@@ -56,13 +128,17 @@ class Tree extends React.Component {
     }
 
     return (
-      <div>
+      <div >
+        <button onClick={this.toggleDocumentFullWidth} className='__better_github_pr_full_width' title='Toggle maximum width of github content' />
         <button onClick={this.onClose} className='close_button'>✖</button>
-        {root.list.map(node => (
-          <span key={node.nodeLabel}>
-            <Branch {...node} visibleElement={visibleElement} />
-          </span>
-        ))}
+        <div>
+          <div className='_better_github_pr_resizer' ref={node => { this.resizer = node }} />
+          {root.list.map(node => (
+            <span key={node.nodeLabel}>
+              <Branch {...node} visibleElement={visibleElement} />
+            </span>
+          ))}
+        </div>
       </div>
     )
   }
diff --git a/src/js/lib.js b/src/js/lib.js
index 82a6380..5cd7080 100644
--- a/src/js/lib.js
+++ b/src/js/lib.js
@@ -34,6 +34,28 @@ const hasCommentsForFileIndex = (fileIndex) => {
   return diffTable.querySelectorAll('.inline-comments').length
 }
 
+export const folderConcat = (node) => {
+  const isFileOrEmpty = (node.list === undefined || node.list.length === 0 || (node.href !== null && node.href !== undefined))
+  if (isFileOrEmpty) {
+    return node
+  }
+
+  const hasSingleChild = (node.list.length === 1)
+  if (hasSingleChild) {
+    const collapsed = folderConcat(node.list[0])
+    const isLastCollapsedIsFolder = node.nodeLabel !== '/' && (collapsed.href === null || collapsed.href === undefined)
+    if (isLastCollapsedIsFolder) {
+      node.nodeLabel = node.nodeLabel + '/' + collapsed.nodeLabel
+      node.hasComments = collapsed.hasComments || node.hasComments
+      node.list = collapsed.list
+    }
+    return node
+  }
+
+  node.list.map(x => folderConcat(x))
+  return node
+}
+
 export const createFileTree = () => {
   const fileInfo = [...document.querySelectorAll('.file-info > a')]
   const files = fileInfo.map(({ title, href }) => {
@@ -68,7 +90,7 @@ export const createFileTree = () => {
     })
   })
   return {
-    tree,
+    tree: folderConcat(tree),
     count: fileInfo.length
   }
 }
diff --git a/src/js/style.css b/src/js/style.css
index f790752..f7399eb 100644
--- a/src/js/style.css
+++ b/src/js/style.css
@@ -7,13 +7,29 @@
     display: none;
 }
 
+._better_github_pr_resizer {
+    position: absolute;
+    width: 5px;
+    height: 100%;
+    background: lightgray;
+    right: 0;
+    top: 0;
+    cursor: col-resize;
+    opacity: .4;
+    transition: opacity .2s ease;
+    z-index: 1;
+}
+
+._better_github_pr_resizer:hover {
+    opacity: 1;
+}
+
 .enable_better_github_pr .__better_github_pr {
     display: block;
     position: relative;
     margin-top: 20px;
-    padding: 10px;
-    width: 240px;
-    overflow: auto;
+    padding: 30px 10px 0;
+    width: 330px;
     height: calc(100vh - 61px);
     background-color: #fafbfc;
     border: 1px solid #e1e4e8;
@@ -22,23 +38,65 @@
 }
 
 .__better_github_pr > div {
-    display: inline-block;
+    overflow: auto;
+    height: 100%;
+    padding-bottom: 10px;
+}
+
+.__better_github_pr > div > div {
+    width: fit-content;
 }
 
 .__better_github_pr .close_button {
     background: none;
     border: none;
     position: absolute;
-    top: 0;
-    right: 0;
+    top: 1px;
+    right: 10px;
     padding: 5px 2px;
 }
 
+.__better_github_pr_full_width {
+    width: 16px;
+    height: 16px;
+    background-size: cover;
+    position: absolute;
+    top: 6px;
+    right: 40px;
+    cursor: pointer;
+    background-image: url('data:image/svg+xml;base64,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');
+    background-color: transparent;
+    border: none;
+}
+
+.__better_github_pr_noselect {
+  -webkit-touch-callout: none; /* iOS Safari */
+    -webkit-user-select: none; /* Safari */
+     -khtml-user-select: none; /* Konqueror HTML */
+       -moz-user-select: none; /* Firefox */
+        -ms-user-select: none; /* Internet Explorer/Edge */
+            user-select: none; /* Non-prefixed version, currently
+                                  supported by Chrome and Opera */
+}
+
+.__better_github_pr_wide .container {
+    min-width: 980px;
+    width: 96% !important;
+}
+
+.__better_github_pr_wide .repository-content .discussion-timeline {
+    width: calc(100% - 220px) !important;
+}
+
+.__better_github_pr_wide .repository-content .discussion-timeline .timeline-new-comment {
+    max-width: 100% !important;
+}
+
 /* GitHub page changes */
 
 .enable_better_github_pr .diff-view,
 .enable_better_github_pr .commit.full-commit.prh-commit {
-    margin-left: 250px;
+    margin-left: 340px;
 }
 
 .enable_better_github_pr .diff-view .file-header {
@@ -51,6 +109,10 @@
     max-width: 708px;
 }
 
+.enable_better_github_pr .container {
+    transition: width .2s ease;
+}
+
 /* react-treeview */
 
 .tree-view_item {